Back in 1999 I took these two photos of pads 39A and B.  The structure on the left of the tower is the Rotating Service Structure that protected the crew cabin and cargo bay of a shuttle on the pad.

The Space Transportation System (STS)
aka the U.S. Space Shuttle Program page 3 

STS-134 Shuttle Discovery - Her last flight was from May 16, 2011 through June 1, 2011
Logo courtesy of NASA